Research On Robotic Chamfering Technology Of Special-Shaped And Thin-Wall Workpiece

In the field of aerospace manufacturing,there are many chamfering processes for special-shaped and thin-walled workpieces.Its processing quality is one of the most important factors affecting the quality and effect of subsequent processes such as welding and assembly.Many workpieces in special fields such as aerospace have characteristics of various structural forms,different sizes,thin-walled structures which are easily deformed by force,and high processing precision.As a result,the automatic processing technology is difficult.Therefore,the chamfering process of the specialshaped and thin-walled workpieces is mostly performed by manual processing up to now,and both efficiency and quality are inferior.In order to solve the problem,this paper will research on the robot chamfering technology for special-shaped and thinwalled workpieces.Firstly,this paper analyzes the characteristics of a special-shaped and thin-walled workpiece's processing and proposes the overall research plan of the processing system.The position information of the curve to be processed is obtained by 3D camera and 3D point cloud processing technology.Then the workpiece is processed by the end flexible chamfering tool,and real-time trajectory error compensation is performed.Secondly,a method for obtaining the position of the curve to be processed by the vision system is proposed.The original point cloud information of the working environment is obtained by a 3D camera,and the point cloud is extracted from the workpiece by using techniques such as point cloud noise reduction and feature separation.The edge point of the workpiece point cloud is extracted based on the microcut plane method.The sliding window algorithm based on the boundary curvature is used to identify the corner feature,and the curve fitting of the edge point is performed to obtain the position information of the curve to be processed.At the same time,a simplified algorithm based on rough boundary extraction is proposed,which effectively improves the computational efficiency of part edge machining curve extraction.Then,the design requirements of the end tool are analyzed,the contact force model of the tool during the machining process is established,and the end chamfering tool of the robot with active and passive flexible links is designed to compensate the deformation in the workpiece machining and control the machining accuracy.The adaptive admittance control algorithm is used to control the feedback force of the tool to ensure the tool's follow-up of the shape of the workpiece,and the online compensation control method of the robot trajectory during the machining process is proposed.Finally,the experimental verification of the robot chamfering technology is carried out.The performance of the adaptive admittance controller is analyzed by the simulation system.The experimental platform of robot chamfering machining was built.The experimental verification of the workpiece edge extraction method and the trajectory compensation control method based on point cloud information was carried out,and the chamfering of the special shaped and thin-wall workpiece was realized.The evaluation and analysis of the error of the intermediate link of the system and the compensation ability of the compensation method and the processing quality of the chamfer are made.